Straddle seats are provided on many different kinds of vehicles, such as motorcycles, snowmobiles and three-wheeled vehicles. Vehicles having straddle seats are used for sport, recreation, and utility purposes. The vehicles may also be used for touring purposes where the driver and one or more passengers remain seated on the vehicle for long periods of time. Straddle-seat vehicles may be operated on different kinds of terrains.
When effecting a turn on a steer-in-direction vehicle such as a snowmobile or an ATV that does not lean (unlike a motorcycle that leans while turning), the driver senses a centrifugal force due to the lateral acceleration of the vehicle. The centrifugal force sensed by the driver is in the direction opposite to the direction in which the vehicle is turning. The driver therefore leans to the inside of the turn to counteract this centrifugal force and to remain on the vehicle. Sometimes, the driver even displaces their hips to the side portion of the seat. Leaning or moving to the inside of the turn counteract the centrifugal force can cause certain be inconveniences. Straddle seats are generally narrower than the driver's body and have a rounded shape with the side portion being generally less cushioned than the central portion of the seat. The less cushioned side portion of the seat thus provides reduced impact absorption to the driver compared the to central seat portion, leading to a bumpier ride for the driver. Additionally, as the driver's hips move to the side, the driver's arms operating the handlebar become misaligned with the spine. The force required for the driver to remain on the seat is also greater while making a turn than when traveling straight.
There is thus a need for a vehicle seat that offers comfortable support to the driver and/or other riders during operation of the vehicle on different kinds of terrains, whether the driver is leaning or upright, turning or travelling straight.